کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1266085 972261 2014 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Synthesis of MnO2 nanoparticles from sonochemical reduction of MnO4− in water under different pH conditions
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
Synthesis of MnO2 nanoparticles from sonochemical reduction of MnO4− in water under different pH conditions
چکیده انگلیسی


• Reduction of MnO4− to MnO2 and MnO2 to Mn2+ could be precisely controlled by sonochemical reduction.
• Solution pH affected the reduction of MnO4− and morphology of the formed MnO2.
• Optimum irradiation time was important to synthesize δ-MnO2 particles with high yields.

MnO2 was synthesized by sonochemical reduction of MnO4− in water under Ar atmosphere at 20 °C, where the effects of solution pH on the reduction of MnO4− were investigated. The obtained XRD results showed that poor crystallinity δ-MnO2 was formed at pH 2.2, 6.0 and 9.3. When solution pH was increased from 2.2 to 9.3, the morphologies of δ-MnO2 changed from aggregated sheet-like or needle-like structures to spherical nanoparticles and finally to cubic or polyhedron nanoparticles. After further irradiation, MnO2 was readily reduced to Mn2+. It was confirmed that H2O2 and H atoms formed in the sonolysis of water acted as reductants for both reduction for MnO4− to MnO2 and MnO2 to Mn2+. The optimum irradiation time for the effective synthesis of MnO2 was 13 min at pH 2.2, 9 min at pH 6.0, 8 min at pH 9.3, respectively.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Ultrasonics Sonochemistry - Volume 21, Issue 5, September 2014, Pages 1629–1634
نویسندگان
, , , ,